Cutting pick and mounting assembly

ABSTRACT

To alleviate the problem associated with wear of either the shank of the cutting pick or the surface defining the cutting pick mounting hole, a cutting pick and mounting assembly is provided including a cutting pick having a shank and a cutting tip, a cutting pick mounting hole extending through a support surface within which the shank of the cutting pick is received such that the cutting tip projects from the hole; an inner sleeve having a cutting pick opening within which the shank of the cutting pick extends; an outer sleeve having an inner sleeve opening within which the inner sleeve and the shank of the cutting pick extend; wherein the shank, the inner sleeve and the outer sleeve are positioned concentrically within the cutting pick mounting hole.

CROSS-REFERENCE TO PRIOR APPLICATION

This application claims priority to Australian Application No.2008230023 filed Oct. 20, 2008, which is incorporated by referenceherein.

FIELD OF THE INVENTION

The present invention relates to cutting tools used for mining andexcavation purposes. The present invention has been developedprincipally for use in the mining of ore and in that use, typicallyunderground ore mining. It will therefore be convenient to describe theinvention in relation to that use although it will be readilyappreciated that the invention could be employed for any mining orexcavation operation to which its function is suitable.

BACKGROUND OF THE INVENTION

Equipment used to mine or excavate in hard earth can include rotarycutters in which a rotating drum that carries a plurality of projectingcutting bits or picks is brought into engagement with an earth face. Thepicks bite into the earth face as they rotate with the drum to impactagainst and to dislodge or fragment earth from the face. Picks employedfor this purpose generally have a hard tungsten carbide tip that isfixed, usually by brazing, to a steel shank. The tip of the pick can beeither of the insert or the cap style. The insert style pick has anelongate tip member anchored within a bore in the leading end of theshank which projects outwardly from the shank. The cap style pickinvolves the tip having a broader base than the insert style tip and thebase is located and brazed into a relatively shallow recess in theleading end of the shank. The present invention is applicable to eitherof these forms of pick.

Picks of the above kind are typically mounted to a cutting assembly,such as a rotating drum, by way of a cutting pick mounting holeextending through a block secured to the drum or through an externalsurface of the drum into which the shank of the cutting pick is insertedand retained. With the shank of the cutting pick inserted into themounting hole, the cutting tip extends outwardly therefrom forengagement with an earth face. In use, the cutting tip bites into theearth face as the drum rotates to impact against and dislodge orfragment earth from the face. This action results in a significantamount of force being translated through the cutting tip and the shankof the cutting pick into the cutting pick mounting hole of the rotatingdrum.

Furthermore, the cutting pick usually is rotatably mounted within themounting hole to permit the pick to wear more evenly, but movement ofpick within the mounting hole is such that over time the shank of thecutting pick and/or the surface of the mounting hole can wear. Over timethe wear may be extensive and result in the shank of the cutting pickbeing worn to the extent that the shank may break or alternatively thesurface of the mounting hole may wear to the extent that it may nolonger effectively be able to retain the shank of the cutting picktherewithin.

The discussion of the background to the invention herein is included toexplain the context of the invention. This is not to be taken as anadmission that any of the material mentioned is considered prior art.

SUMMARY

To alleviate the problem associated with wear of either the shank of thecutting pick or the surface defining the cutting pick mounting hole, thepresent invention provides a cutting pick and mounting assemblyincluding a cutting pick having a shank and a cutting tip, a cuttingpick mounting hole extending through a support surface within which theshank of the cutting pick is received such that the cutting tip projectsfrom the hole; an inner sleeve having a cutting pick opening withinwhich the shank of the cutting pick extends; an outer sleeve having aninner sleeve opening within which the inner sleeve and the shank of thecutting pick extend; wherein the shank, the inner sleeve and the outersleeve are positioned concentrically within the cutting pick mountinghole.

The arrangement between the shank, the inner sleeve, the outer sleeveand the mounting hole is such that upon the cutting pick being subjectedto a load which tends to cause movement of the cutting pick relative tothe mounting hole, that movement can cause movement of the inner sleeverelative to the outer sleeve. Movement of the cutting pick and thecutting pick shank relative to the mounting hole can cause movement ofthe inner sleeve relative to the outer sleeve, whereby either or both ofthe sleeves can wear sacrificially instead of the cutting pick, theshank of the cutting pick and/or the cutting pick mounting hole.Consequently, an advantage of the invention is that wear of the cuttingpick mounting hole and/or the cutting pick or the shank of the cuttingpick upon movement of the cutting pick and the shank of the cutting pickrelative to the mounting hole can be reduced.

In one form, the outer sleeve remains substantially stationary relativeto the cutting pick mounting hole such that in use when the cutting pickengages an earth face, any axial or lateral movement of the cutting pickrelative to the mounting hole results in sacrificial wearing of theinner sleeve and/or the outer sleeve rather than wear occurring in theshank of the cutting pick or the surface of the cutting pick mountinghole.

One purpose of sacrificial wearing of the inner sleeve and/or the outersleeve is to reduce or eliminate the amount of wear encountered by partsof the cutting pick which would normally encounter wear as a result ofrelative movement of the cutting pick and the mounting hole and inparticular the shank of the cutting pick. Another purpose is to reducethe amount of wear encountered in sections of the cutting pick mountinghole which would normally wear as a result of relative movement of thecutting pick and the mounting hole. Thus, the above arrangement isparticularly advantageous in extending the useful life of the cuttingpick and the cutting pick mounting hole and in turn the useable life ofthe cutting assembly, such as a cutter support and a rotary cutter orany other form of cutter, or of a piece of mining or excavationequipment incorporating one or more of the cutting pick and mountingassemblies disclosed herein.

Another advantage of the cutting pick and mounting assemblies disclosedherein is that the outer sleeve can be used to fill a gap between aradially outwardly facing surface of the shaft of the inner sleeve andthe facing surface of the cutting pick mounting hole which may resultover time due to wearing of the surface of the cutting pick mountinghole. As the gap becomes larger then outer sleeves of greaterthicknesses can be used to fill or take up the gap.

In one form, the outer sleeve is a substantially annular member havingan inner surface that defines the inner sleeve opening and that isconfigured to face a facing surface of the inner sleeve. The outersleeve can also have an outer surface that is configured for face toface contact with a facing surface of the cutting pick mounting hole.

The outer sleeve can include at least one hole extending partially orfully between the inner surface and the outer surface for facilitatingthe removal of the outer sleeve either from around the inner sleeve orfrom within the cutting pick mounting hole, such as by a suitable toolthat engages the hole.

In one form, the outer sleeve is substantially cylindrical. The outersleeve can be formed out of a sheet of metal which is rolled into asubstantially annular configuration.

The outer sleeve can include a longitudinal slit to enable the diameterof the inner sleeve opening to be expanded or contracted. Thelongitudinal slit can extend in substantially the same direction as alongitudinal axis of the inner sleeve opening of the outer sleeve.

In one form, the inner sleeve is a substantially annular member havingan inner surface that defines the cutting pick opening and is configuredfor face to face contact with the shank of the cutting pick and an outersurface that is configured to face the outer sleeve.

In another form, the inner sleeve includes a pair of longitudinallyspaced apart ridges on the outer surface for retaining the inner sleevewithin the inner sleeve opening of the outer sleeve by abutting againstopposite ends of the outer sleeve.

The cutting pick and mounting assembly can further include a firstrecess in one of the inner sleeve or the cutting pick mounting hole forreceiving a locking element for releasably locking the inner sleevewithin the cutting pick mounting hole.

In another form, the assembly can include a recess on one of the innersleeve or the shank of the cutting pick for receiving a locking elementfor releasably locking the cutting pick within the inner sleeve.

In one form, the inner sleeve includes a shaft and a shoulder at one endof the shaft surrounding the cutting pick opening. The shoulder can beconfigured for abutment with the cutting pick to prevent or restrictaxial movement of the cutting pick relative to the inner sleeve when theshank of the cutting pick is inserted within the cutting pick opening ofthe inner sleeve. The shoulder can also be configured for abutment witha surface surrounding the cutting pick mounting hole to limit the extentto which the shaft of the inner sleeve and/or the outer sleeve isinsertable into the cutting pick mounting hole.

The shoulder can have a first surface which is annular and orientedtransversely to a longitudinal axis of the cutting pick opening forabutment with a flanged portion of the cutting pick shank.

The shoulder can have a second surface which is annular and orientedtransversely to a longitudinal axis of the cutting pick opening forfacing a surface surrounding the opening of the cutting pick mountinghole. The second surface can include at least one protuberance forabutment with the surface surrounding the cutting pick mounting hole.The surface which extends circumferentially around the shoulder can beof a tapering annular form.

The outer sleeve can be independently positionable within the cuttingpick mounting hole for subsequently receiving the inner sleeve and theshank of the cutting pick through the inner sleeve opening thereof.

The outer sleeve can be configured to receive the inner sleeve throughthe inner sleeve opening in a snap-fit locking engagement.

The invention also provides an inner sleeve configured for use in thecutting pick and mounting assembly of any one of the forms set outabove.

The invention also provides a cutting pick having a shank which ispositioned within a cutting pick opening of an inner sleeve for use inthe cutting pick and mounting assembly of any one of the forms set outabove. The cutting pick can have a cutting tip fixed to one end of theshank which projects from the shank and which is of a material that isharder than the material of the shank.

The invention also provides an outer sleeve configured for use in thecutting pick and mounting assembly of any one of the forms set outabove.

The invention also provides a mounting assembly comprising an outersleeve positioned within a cutting pick mounting hole of a cutting picksupport, for use in the cutting pick and mounting assembly of any one ofthe forms set out above.

The invention also provides a cutting pick configured for use in thecutting pick and mounting assembly of any one of the forms set outabove.

The invention also provides a wear sleeve for use in a cutting pick andmounting assembly of a cutting assembly, the wear sleeve including asubstantially annular member having a radially inwardly facing surfacethat defines a longitudinally extending cutting pick opening forreceiving a shank of a cutting pick therethrough and an oppositeradially outwardly facing surface that includes a pair of longitudinallyspaced apart ridges.

Further aspects and concepts will become apparent to those skilled inthe art after considering the following description and claims inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which are incorporated in and constitute apart of the specification, embodiments of the invention are illustrated,which together with a general description of the invention given above,and the detailed description below serve to exemplify embodiments of theinvention;

FIG. 1 is a perspective view of an inner sleeve and an outer sleeve of acutting pick and mounting assembly wherein the inner sleeve is fittedwithin an inner sleeve opening of an outer sleeve in a snap fit lockingengagement.

FIG. 2 is a perspective view of the inner sleeve of FIG. 1.

FIG. 3 is a side view of the inner sleeve and the outer sleeve of FIG. 1wherein the inner sleeve is fitted within the inner sleeve opening ofthe outer sleeve in a snap fit locking engagement.

FIG. 4 is a side view of a cross section of the inner sleeve and theouter sleeve of FIG. 1 taken along the section line 4-4 in FIG. 3.

FIG. 5 is a side view of the inner sleeve of FIG. 1.

FIG. 6 is a side view of a cross section of the inner sleeve of FIG. 1taken along the section line 6-6 in FIG. 5.

FIG. 7 is a perspective view of the outer sleeve of FIG. 1.

FIG. 8 is a top view of the outer sleeve of FIG. 1.

FIG. 9 is a side view of a cross-section of the cutting pick andmounting assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 to 9 there is shown a cutting pick and mountingassembly 5 (See FIG. 9), and components thereof, in accordance with anembodiment of the invention disclosed herein. The cutting pick andmounting assembly 5 is mounted to a cutting pick mounting block 2 toform part of a cutting assembly which can include a rotary cutter, orany other form of cutter, of a piece of mining or excavation equipment(not shown).

The cutting pick and mounting assembly 5 includes a cutting pick 10, aninner sleeve 30 and an outer sleeve 40. The cutting pick 10 includes ashank 12 that is receivable within a cutting pick opening 32 within theinner sleeve 30. The inner sleeve 30 is receivable within an innersleeve opening 42 within the outer sleeve 40 which in turn is receivablewithin a cutting pick mounting hole 20 extending through a supportsurface 24 of the cutting pick mounting block 2. Accordingly, the shank12, the inner sleeve 30 and the outer sleeve 40 are positionedconcentrically within the cutting pick mounting hole 20. The cuttingpick and mounting assembly 5 is advantageous in that the arrangementbetween the shank 12, the inner sleeve 30, the outer sleeve 40 and themounting hole 20 is such that upon the cutting pick 10 being subjectedto a load which tends to cause movement of the cutting pick 10 relativeto the mounting hole 20, that movement causes movement of the innersleeve 30 relative to the outer sleeve 40. Movement of the cutting pick10 and the shank 12 relative to the mounting hole 20 causes movement ofthe inner sleeve 30 relative to the outer sleeve 40, whereby the innersleeve 30 and/or the outer sleeve 40 can wear sacrificially instead ofthe cutting pick 10, or the shank 12 thereof, and/or a surface 22defining the cutting pick mounting hole 20. The provision of the outersleeve 40 can also provide the advantage of preventing abrasion and/orwearing of the surface 22 of the cutting pick mounting hole 20.Consequently, an advantage of the cutting pick and mounting assembly 5is that wear of the cutting pick mounting hole 20 and/or the cuttingpick shank 12 upon movement of the cutting pick shank 12 relative to themounting hole 20 can be reduced.

Another advantage of the provision of the outer sleeve 40 is that theouter sleeve 40 can facilitate filling in of any space between thesurface 22 of the cutting pick mounting hole 20 and the inner sleeve 30which can arise as a result of abrasion and/or wearing of the surface22. Other advantages of forms of the invention disclosed herein will beapparent in view of the following detailed description.

Referring to FIG. 1 there is shown the inner sleeve 30 with the outersleeve 40 fitted thereto. The inner sleeve 30 is an annular member madeup of a substantially cylindrically shaped shaft 39 with a shoulder 50at one end. The shaft 39 has the cutting pick opening 32 extendinglongitudinally therethrough. The shaft 39 also has a radially outwardlyfacing substantially cylindrical surface 36 and a radially inwardlyfacing substantially cylindrical surface 34 wherein the radiallyinwardly facing surface 34 defines the cutting pick opening 32 within ofthe shaft 39. The shoulder 50 is integrally formed at one end of theshaft 39. The shoulder 50 thus forms a flange at the top of the innersleeve 30. The shoulder 50 has a first or upper annular shaped surface52 which faces away from the shaft 39 and an opposite second or lowerannular surface 54 which faces towards the shaft 39. The shoulder 50farther includes an annular lateral surface 58 which extends between theupper surface 52 and the lower surface 54. The lateral surface 58 ispartially tapered towards the upper annular surface 52 of the shoulder50 and the lateral surface 58 extends around the circumference of theshoulder 50.

As shown in FIGS. 1, 3, 4 and 9 the shaft 39 of the inner sleeve 30 withthe outer sleeve 40 fitted thereto is insertable into the cutting pickmounting hole 20 of the rotary cutter, or any other form of cutter, ofthe mining or excavation equipment. When the inner sleeve 30 with theouter sleeve 40 fitted thereto is inserted into the cutting pickmounting hole 20, the lower surface 54 of the shoulder 50 faces towardsthe supporting surface 24 surrounding the cutting pick mounting hole 20.The lower surface 54 of the shoulder 50 also includes a pair ofprotuberances 56 on radially opposite sides of the shaft 39. Theprotuberances 56 project downwardly from the lower surface 54 of theshoulder 50 such that when the shaft 39 of the inner sleeve 30 with theouter sleeve 40 fitted thereto is inserted into the cutting pickmounting hole 20, the protuberances 56 abut against the surface 24surrounding the cutting pick mounting hole 20 to limit the extent towhich the shaft 39 of the inner sleeve 30 and/or the outer sleeve 40 isinsertable into the cutting pick mounting hole 20. Alternatively, theouter sleeve 40 can be fitted independently within the cutting pickmounting hole 20 and the shaft 39 of the inner sleeve 30 subsequentlyfitted within the inner sleeve opening 42 of the outer sleeve 40 andthereby fitted within the cutting pick mounting hole 20.

The radially outwardly facing surface 36 of the shaft 39 of the innersleeve 30 includes a first recess 35. The recess 35 is in the form of aradial groove which extends circumferentially about the radiallyoutwardly facing surface 36 of the shaft 39 to form an annular groovetherein. The first recess 35 is configured to receive a first lockingelement 25 which in the embodiment illustrated in FIG. 9 is in the formof a locking ring. The locking element fits within the first recess 35and projects radially outwardly from the first recess 35 and theradially outwardly facing surface 36 of the shaft 39. The first lockingelement 25 has a diameter which is greater than the diameter of thecutting pick mounting hole 20 and/or the diameter of the inner sleeveopening 42 of the outer sleeve 40. Thus, the first locking element 25 isunable to pass through the inner sleeve opening 42 of the outer sleeve40 and/or the cutting pick mounting hole 20 when the first lockingelement 25 is fitted to the first recess 35 after the shaft 39 of theinner sleeve 30 is fitted within the outer sleeve 40 and within thecutting pick mounting hole 20. The first locking element 25 can beremovably fitted to first recess 35 to releasably lock the shaft 39 ofthe inner sleeve 30 within the cutting pick mounting hole 20. The firstlocking element 25 can take any suitable form as long as it achieves thefunction of inter-engaging with the first recess 35 to releasably lockthe inner sleeve 30 within the cutting pick mounting hole 20. The firstlocking element 25 can be a biased or sprung locking member such as aring or a U-shaped member.

As illustrated in FIG. 9, the shank 12 of the cutting pick 10 has acutting tip 14 fixed to one end of the shank 12 which projects from theshank 12 and which is made of a material that is harder than thematerial of the shank 12. For example, the material forming the shankcan be a cast metal. However, the material forming the cutting tip 14 ispreferably made out of a material that is relatively harder than thematerial forming the shank 12 of the cutting pick 10. For example, thematerial forming the cutting tip 14 can be formed out of silicon carbide(SiC), an oxide of aluminium (Al₂O₃), a titanium alloy, titanium nitride(TiN), silicon carbide diamond composite (SiC-D), cubic boron nitride,tool steel or other like materials. These materials can be formed as acomposite material with other suitable materials or they can be providedas an outer layer or layers over a suitable base to form the cutting tip14. The cutting tip 14 can be either of the insert or cap type. The captype is illustrated in FIG. 9. The cap type involves the cutting tip 14having a shorter axial length than in the insert type. The cutting tip14 in both instances is mounted within a bore 15 which is within one endof the shank 12 of the cutting pick 10. The cutting tip 14 is brazedwithin the bore 15 to maintain it securely therewithin. The shank 12 ofthe cutting pick 10 is a substantially cylindrically shaped solid rodmade of any suitable material such as a metal alloy.

As can be seen in FIG. 9, the shank 12 of the cutting pick 10 isinsertable within the cutting pick opening 32 within the inner sleeve30. The radially outwardly facing cylindrically shaped surface 13 of theshank 12 is configured for face to face contact with the radiallyinwardly facing surface 34 of the inner sleeve 30 when the shank 12 ofthe cutting pick 10 is inserted within the shank the cutting pickopening 32 of the inner sleeve 30. The radially inwardly facing surface34 of the shaft 39 of the inner sleeve 30 includes a second recess 37.The second recess 37 is in the form of an annular groove in the radiallyinwardly facing surface 34 of the shaft 39. The radially outwardlyfacing surface 13 of the shank 12 of the cutting pick includes arecessed annular groove 17. The second recess 37 and/or the annulargroove 17 are configured to receive a second locking element 16. Thesecond locking element 16 can be fitted between the second recess 37 andthe annular groove 17 to lock the shank 12 of the cutting pick 10 withinthe cutting pick opening 32 within the inner sleeve 30. The secondlocking element 16 can be a biased or sprung locking member such as aring or a U-shaped member. Accordingly, the second locking element 16can be sprung or otherwise resiliently mounted such that when the shank12 of the cutting pick 10 is inserted in the cutting pick opening 32 ofthe inner sleeve 30 the second locking element 16 can be depressedwithin the annular groove 17 in the radially outwardly facing surface 13of the shank 12 so as to enter the cutting pick opening 32. When theshank 12 has been sufficiently inserted within the cutting pick opening32 of the inner sleeve 30 the second locking element 16 can resilientlyproject into the second recess 37 to releasably lock the shank 12 of thecutting pick 10 within the cutting pick opening 32 of the inner sleeve30.

The cutting pick 10 includes a flanged portion 11 atop the shank 12 ofthe cutting pick 10 configured for abutment with the upper surface 52 ofthe shoulder 50 to prevent or restrict axial movement of the cuttingpick 10 relative to the inner sleeve 30 when the shank 12 of the cuttingpick 10 is inserted within the cutting pick opening 32 of the innersleeve 30. In particular, the flanged portion 11 abuts against the uppersurface 52 of the shoulder 50 to prevent the shank 12 of the cuttingpick 10 passing entirely within the cutting pick opening 32 of the innersleeve 30.

As shown in FIGS. 1, 3, 4, 7, 8 and 9, the outer sleeve 40 is an annularmember that has a substantially cylindrical overall shape. The outersleeve 40 is formed out of a sheet of any suitable material such assteel, a metal alloy or any other suitable material which can be rolledinto an annular or tubular shape. Alternatively, the outer sleeve 40 canbe molded or extruded into an annular or tubular shape. The outer sleeve40 includes a radially outwardly facing surface 46 and a radiallyinwardly facing surface 44. Accordingly, the radially inwardly facingsurface 44 defines the inner sleeve opening 42 which extends from thelower end 41 to the upper end 43 of the outer sleeve 40. Furthermore,the outer sleeve 40 includes a longitudinal slit 48 which extends from alower end 41 to an upper end 43 of the outer sleeve 40.

As shown in FIGS. 1 to 6 and 9 the inner sleeve 30 includes first andsecond ridges 31, 33 on the radially outwardly facing surface 36 of theshaft 39. The first and second ridges 31, 33 are longitudinally spacedapart from each other and from the first recess 35 on the radiallyoutwardly facing surface 36 of the inner sleeve 30 with the second ridge33 located immediately adjacent to the lower surface 54 of the shoulder50 and the protuberance 56 of the shoulder 50. The first ridge 31 has asloping surface 31 a and an opposite abutting surface 31 b. The slopingsurface 31 a of the first ridge 31 faces away from the shoulder 50 whilethe abutting surface 31 b faces towards the shoulder 50. Thus, when theshaft 39 of the inner sleeve 30 is inserted within the inner sleeveopening 42 of the outer sleeve 40 the upper end 43 or the lower end 41of the annular outer sleeve 40 meets and slides over the sloping surface31 a of the first ridge 31. The outer sleeve 40 is configured to enablethe shaft 39 of the inner sleeve 30 to be inserted within the innersleeve opening 42 such that the radially inwardly facing surface 44 ofthe outer sleeve 40 faces the radially outwardly facing surface 36 ofthe shaft 39 of the inner sleeve 30. By including the longitudinal slit48 which extends from the lower end 41 to the upper end 43 the diameterof the inner sleeve opening 42 of the outer sleeve 40 can be expandedslightly to enable the upper end 43, the lower end 41 and the radiallyinwardly facing surface 44 of the outer sleeve 40 to slide over thesloped surface 31 a of the first ridge 31. This is because the firstridge 31 of the radially outwardly facing surface 36 of the shaft 39 ofthe inner sleeve 30 has a slightly larger diameter than the diameter ofthe inner sleeve opening 42 of the outer sleeve 40 in its unexpandedstate. Similarly, the second ridge 33 also has a slightly largerdiameter than the diameter of the inner sleeve opening 42 of the outersleeve 40 in its unexpanded state. After the radially inwardly facingsurface 44 of the outer sleeve 40 has slid over the sloped surface 31 aof the first ridge 31 the outer sleeve 40 is positioned between thefirst ridge 31 and the second ridge 33 on the radially outwardly facingsurface 36 of the inner sleeve 30 with the upper end 43 of the outersleeve abutting against the second ridge 33 and the lower end 41abutting against the abutting surface 31 b of the first ridge 31. Thus,the outer sleeve 40 is releasably retained between the longitudinallyspaced apart first and second ridges 31, 33 on the radially outwardlyfacing surface 36 of the shaft 39 of the inner sleeve 30.

As will be appreciated, the cutting pick and mounting assembly 5 in theassembled configuration involves the shank 12 of the cutting pick 10being inserted within the cutting pick opening 32 of the inner sleeve 30and being releasably retained or locked therewithin. The shaft 39 of theinner sleeve 30 is inserted within the inner sleeve opening 42 of theouter sleeve 40 and is releasably retained therewithin. The cutting pick10, the shaft 39 of the inner sleeve 30 and the outer sleeve 40 areinserted in their assembled configuration within the cutting pickmounting hole 20 and are releasably retained therewithin by theinteraction between the first recess 35 on the shaft 39 of the innersleeve 30 and the first locking element 25 in the manner describedabove.

Accordingly, as shown in FIG. 9, the radially outwardly facing surface46 of the outer sleeve 40 is in face to face engagement with the surface22 defining the cutting pick mounting hole 20. When the cutting pick andmounting assembly 5 is in use and the cutting pick 10 is brought intoengagement with an earth face and the cutting pick and mounting assembly5 is moved relative to the earth face the cutting pick 10 and the shank12 thereof are subjected to axial and/or lateral movement relative tothe cutting pick mounting hole 20. The axial and/or lateral movement ofthe cutting pick 10 relative to the cutting pick mounting hole 20 istransmitted through the inner sleeve 30 as axial and/or lateral and/orrotational movement thereof relative to the cutting pick mounting hole20. The outer sleeve 40 which surrounds the shaft 39 of the inner sleeveremains substantially stationary relative to the cutting pick mountinghole 20 such that movement of the inner sleeve 30 relative to thecutting pick mounting hole 20 results in movement of the inner sleeve 30relative to the outer sleeve 40. Movement of the inner sleeve 30relative to the outer sleeve 40 results in the radially outwardly facingsurface 36 of the inner sleeve 30 and the radially inwardly facingsurface 44 of the outer sleeve 40 rubbing against each other whichcauses friction and/or abrasion therebetween. Thus, the inner sleeve 30and/or the outer sleeve 40 are sacrificially worn as a result of thefriction and/or abrasion therebetween.

The purpose of this sacrificial wearing of the inner sleeve 30 and/orthe outer sleeve 40 is to reduce the amount of wear encountered by thecutting pick 10 and in particular the shank 12 thereof and to reduce theamount of wear encountered by the cutting pick mounting hole 20 and inparticular the surface 22 defining the cutting pick mounting hole 20.Thus, the above arrangement is particularly advantageous in extendingthe usable life of the cutting pick 10 and the cutting pick mountinghole 20 and in turn the useable life of the cutting assembly, such as arotary cutter or any other form of cutter, of a piece of mining orexcavation equipment incorporating one or more of the cutting pickmounting holes 20.

Another advantage of the above arrangement is that the outer sleeve 40can fill a gap between the radially outwardly facing surface 36 of theshaft 39 of the inner sleeve 30 and the surface 22 defining the cuttingpick mounting hole 20 which may result over time due to wearing of thesurface 22 defining the cutting pick mounting hole 20.

The invention has been described herein with reference to preferredembodiments. Modification and alteration may occur to persons skilled inthe art upon reading and understanding this specification. It isintended to include all such modifications and alterations in so far asthey fall within the scope of the following claims or equivalencethereof.

Although the present invention has been described in connection withpreferred embodiments thereof, it will be appreciated by those skilledin the art that additions, deletions, modifications, and substitutionsnot specifically described may be made without department from thespirit and scope of the invention as defined in the appended claims.

1. A cutting pick and mounting assembly, comprising: a cutting pickhaving a shank and a cutting tip, a cutting pick mounting hole extendingthrough a support surface within which the shank of the cutting pick isreceived such that the cutting tip projects from the hole; an innersleeve having a cutting pick opening within which the shank of thecutting pick extends; an outer sleeve having an inner sleeve openingwithin which the inner sleeve and the shank of the cutting pick extend;wherein the shank, the inner sleeve and the outer sleeve are positionedconcentrically within the cutting pick mounting hole.
 2. The cuttingpick and mounting assembly of claim 1, wherein the outer sleeve is asubstantially annular member having a radially inwardly facing surfacethat defines the inner sleeve opening and that is configured to face afacing surface of the inner sleeve and a radially outwardly facingsurface that is configured for face to face contact with a facingsurface of the cutting pick mounting hole.
 3. The cutting pick andmounting assembly of claim 2, wherein the outer sleeve includes at leastone hole extending between the inwardly facing surface and the outwardlyfacing surface for facilitating the removal of the outer sleeve eitherfrom around the inner sleeve or from within the cutting pick mountinghole.
 4. The cutting pick and mounting assembly according to claim 1,wherein the outer sleeve is substantially cylindrical.
 5. The cuttingpick and mounting assembly according to claim 1, wherein the outersleeve includes a longitudinal slit to enable the diameter of the innersleeve opening to be expanded or contracted.
 6. The cutting pick andmounting assembly of claim 5, wherein the longitudinal slit extends insubstantially a same direction as a longitudinal axis of the innersleeve opening of the outer sleeve.
 7. The cutting pick and mountingassembly according to claim 1, wherein the outer sleeve is formed out ofa sheet of metal which is rolled into a substantially annularconfiguration.
 8. The cutting pick and mounting assembly according toclaim 1, wherein the inner sleeve is a substantially annular memberhaving a radially inwardly facing surface that defines the cutting pickopening and is configured for face to face contact with the shank of thecutting pick and a radially outwardly facing surface that is configuredto face a facing surface of the outer sleeve.
 9. The cutting pick andmounting assembly of claim 8, wherein the inner sleeve further includesa pair of longitudinally spaced apart ridges on the radially outwardlyfacing surface for retaining the inner sleeve within the inner sleeveopening of the outer sleeve by abutting against opposite ends of theouter sleeve.
 10. The cutting pick and mounting assembly of claim 1,further including a first recess in one of the inner sleeve or thecutting pick mounting hole for receiving a locking element forreleasably locking the inner sleeve within the cutting pick mountinghole.
 11. The cutting pick and mounting assembly of claim 1, furtherincluding a recess on one of the inner sleeve or the shank of thecutting pick for receiving a locking element for releasably locking thecutting pick within the inner sleeve.
 12. The cutting pick and mountingassembly of claim 1, wherein the inner sleeve includes a shaft and ashoulder at one end of the shaft surrounding the cutting pick opening.13. The cutting pick and mounting assembly of claim 12, wherein theshoulder has a first surface which is annular and oriented substantiallytransversely to a longitudinal axis of the cutting pick opening forabutment with a flanged portion of the cutting pick shank.
 14. Thecutting pick and mounting assembly of claim 12, wherein the shoulder hasa second surface which is annular and oriented substantiallytransversely to a longitudinal axis of the cutting pick opening forfacing a surface surrounding the cutting pick mounting hole.
 15. Thecutting pick and mounting assembly of claim 14, wherein the secondsurface of the shoulder includes at least one protuberance for abutmentwith the surface surrounding the cutting pick mounting hole.
 16. Thecutting pick and mounting assembly of claim 12, wherein a taperingannular surface extends circumferentially around the shoulder.
 17. Thecutting pick and mounting assembly of claim 1, wherein the outer sleeveis independently positionable within the cutting pick mounting hole forsubsequently receiving the inner sleeve and the shank of the cuttingpick through the inner sleeve opening thereof.
 18. The cutting pick andmounting assembly of claim 1, wherein the outer sleeve is configured toreceive the inner sleeve through the inner sleeve opening in a snap-fitlocking engagement.
 19. An inner sleeve configured for use in thecutting pick and mounting assembly of claim
 1. 20. A cutting pick havinga shank which is positioned within a cutting pick opening of an innersleeve for use in the cutting pick and mounting assembly of claim
 1. 21.An outer sleeve configured for use in the cutting pick and mountingassembly of claim
 1. 22. A mounting assembly in which an outer sleeve ispositioned within a cutting pick mounting hole for use in the cuttingpick and mounting assembly of claim
 1. 23. A cutting pick configured foruse in the cutting pick and mounting assembly of claim
 1. 24. A wearsleeve for use in a cutting pick and mounting assembly of a cuttingassembly, comprising: a substantially annular member having a radiallyinwardly facing surface that defines a longitudinally extending cuttingpick opening for receiving a shank of a cutting pick therethrough and anopposite radially outwardly facing surface that includes a pair oflongitudinally spaced apart ridges.